Direct-combustion grate-burning process with separate distillation and combustion ofthe fuel



Invew/Z'ar B. MEYER. v DIRECT COMBUSTION GRATE BURNING PROCESS WITH SEPARATE D|sT ||.1 AT| N AND COMBUSTION bF THE Fun-11.

' FILED MAR- 21, 1921.-

h up ire BRUNO MEYER, OF BERLIN-CHARLOTTENBURG, GERMANY, AS SIGNOR TOtTHE FIRM JULIUS PINTSCH AKTIENGESELLSCHAFT, OF BERLIN, GERMANY.

DIRECT-COMBUSTION GRATE-I BURNING PROCESS WITH SEPARATE DISTILLATION AND COMBUSTION OF THE FUEL.

Application filed March 21, 1921.

Serial No. 454,130.

(GRANTED UNDER THE PROVISIONSQF THE ACT OF MARCH 3, 1921, 41 STAT. L, 1313.)

T 0 all whom it may concern: Be it known that I, BRUNO MEYER, a citizen of the Republic of Germany, residing at Berlin-Charlottenburg, Germany, have invented a new and useful Direct-Combustion Grate-Burning Process with Separate DIS- tillation and Combustion of the Fuel (for which I have filed application in Germany, December 11, 1917, Patent No. 339,?29, August 6, 1921), of which the following 1s a specification.

That the burning of coal is attended with a great waste of its constituent parts the conservation of which would be a great pub lic benefit is a fact that is becoming more and more widely known. The first attempts in this direction led to the recovery of the by-products by the distillation of the coal in gas generators and the subsequent burning of the gas beneath the boilers. But this process is expensive because on the one hand a considerable amount of heat is lost which has to be made up for by an additionalcoal consumption and on the other hand the construction and working of the gas generatln plant involve considerable expenditure thfi the by-products.

But vastly improved conditions Wlll be obtained if the coal is treated according to the novel process hereinafter described. An application of this process is illustratedin the drawing which represents a longitudinal section of a boiler wlth a travelling grate. Hitherto the coal was fed from the coal bunker a onto the travelling grate b where it was burnt to ashes. According-to the present invention a distillation shaft or trunk c is interposed between a and b and connected by a pipe (Z with a by-product recovery plant, 6 and a gas exhauster f by which a small portion of the gases of combustion formed on the grate b is drawn through the shaft 0 and the plant e. By this means tar, ammoniac etc. is recovered and separated whilst the residual permanent ,gases of this mixture of gases of combustion and distillation are sent back by the exhauster f to the combustion chamber of the boiler where they issue from the burner g or at any other partof the furnace.

To separate the volatile components contained in the coal it is not by any means necessary to draw the whole of the gases obtamed by combustion through the feed shaft 0, a comparatively small amount of these gases being suflicient for this purpose and a large proportion of the same being reduced to carbon monoxide and hydrogen in the bottom end of the shaft 0 by the action of the incandescent carbon that will be present there. This gas mixture mixes in the upper part of the shaft 0 with gases of distillation and passes out of the shaft at a low temperature without the valuable constituents (tar and ammonia) being destroyed, which very often happens in distillation shafts that are heated from the exterior. It follows from the preceding paragraphs that the invention contemplates a direct grate-combustion in which with the aid of correspo ding quantities of air, the entire fuel is c mpletely burnt to carbon dioxide and steam, i. e., the new process differs en-' tirely from the process that takes place above the grate of a gastgenerator inasmuch as the process of distilling the fuel in the generator 1s done away with. is seldom covered by the profit derived fro I A clear distinction has sofar been made between the two processes-viz, the production of gas in generators and the two principal distillation processes in the manufacture of coke and lighting-gaswhich have hitherto enabled the valuable by-products ofcoal ,to be recovered, and the direct combustion of coal on furnace grates, which does not permit of the utilization of the by-products, because the object of the invention is to entirely change this state of things by providing means by which a by-products of coal, especially of the lowtemperature-tar that is now so frequently mentioned, can be successfully carried out in connection with ordinary grate fires even in the smallest plants, as for instance in connection with steam boilers.

The principal advantages of the new process as compared to the only'processes that have hitherto been employed for recovering the by-products of coal, viz, gas production by generators and the two esses' used in producing coke and lightinggas consist in the following two points:

1. In the direct burning of coke that has recovery of the valuable" distillation procbeen produced in coke ovens or gas retorts Considerable amounts of heat are wasted through the coke thus produced having to be cooled off, whereas the heat that is taken up by the coke formed in the distillation shaft in accordance with the present invention is restored by it to the furnace.

2. In the case of gas furnaces the losses of heat in the gas producer are added to the loss in the furnace so that the former give rise to an increase of the fuel consumed. Besides the working of producers is generally more troublesome'and dearer because to reduce the carbon dioxide and steam the layer of fuel has to be kept even and to accomplish this considerable care has to be taken to prevent hollow spaces being formed by the slags, which is out of the question in the direct combustion process in which the coal is burnt in thin layers. Another point is that in working with gas producers a large amount of steam must generally be used to prevent the formation of slags. Hence it is also necessary to conduct a larger quantity of the gases formed in the gas producing chamber through the distillation chamber so to maintain in this latter the temperature required for gas formation. This involves the cooling and cleaning of larger quantities of gas than in the process according to the invention, which entails an increase of the costs of the recovery of the by-products.

I claim:

1. A direct combustion grate-burning process with separate distillation and combustion of the fuel consisting in feeding the,

fuel from a fuel supply through a distillacondition required for the formation of ammoniac and low temperature tar, conducting the products of distillation from the distillation chamber, cooling and cleaning the products of distillation for the purpose of separating the valuable by-products, and finally conducting the gases of distillation back to the combustion chamber of the furnace.

2. A direct combustion grate-burning process with separate distillation and combustion of the fuel consisting in feeding the fuel from a fuel supply through a distilla tion chamber and into a combustion chamber, passing a suflicient amount of the combustion gases from the combustion chamber through the distillation chamber to maintain the fuel in the distillation chamber at a temperature required for the formation of ammoniac and low temperature ta l, withdrawing the products of distillation from the distillation chamber, cleaning and cooling the distillation products for the purpose of separating the valuable by-products from the distillation gases, and forcing the diluted gases into the combustion chamber. and burning the same therein.

In testimony whereof I affix my signa ture.

' BRUNO MEYER.- 

